Rotary electric furnace.



NO- 825,058. PATENTED JULY 3, 190R.

W. MoA. JOHNSON. ROTARY ELECTRIC FURNACE.

APPLICATION FILED 061.13. 1903.

Jag/s;

UNITED p sTAT s PATENT OFFICE;

WOOLSEY MoA; JOHNSON, OF IOLA, KANSAS.

7 metal.

The furnace comprises, essentially, a rotatable cylindrical bedyiprovided with a refractory lining, suitable end plates or closures, and meanswithin the walls-for devel oping the necessary temperature.

Fora clear understandingof my invent on reference 1s made to the accompanying drawings, wherein' Fi ure 1 is a central longitudinal section of one orIn of my furnace mounted in 'an mchned position, and F1' '..2 is'a transverse see- I .tio'n thereof on line II I of Fig. 1.

Referring to said figures, the body of the 'furnaceis shown as consisting of a plurality of transverse sections 1 1,01 cast-iron, and cast-iron end plates 2 2. Each of said sections 1 isprovided with a lining 3 of refractory brick or fireproof composition, which may be acid, neutral, or basic, in accordance with the character of the ore to be treated.

Said sections are provided with flan es 4 at their abuttingqen'ds, and inassemb ng the furnace gaskets or plates'5, of asbestos or other refractory insulating material, are clamped between the several sections and between said sectionsand the end plates 2 by means of insulated bolts, as clearly indicated in Fig. 1. In this manner a substantially air-tight structure is provided composed of several independent and electricallyinsulated parts, whereby loss of current by leakage through the furnace walls between the terminals is reduced to a minimum or entirely obviated. While I consider such sectional construction to be preferable, I do not limit myself thereto. =The ,furnace is preferably mounted, as shownfin an inclined position, and suitable doors 6 7 for the intitoduction of the charge and the withdrawal of the residuum are provided at the ends.

.8 8 represent. a plurality of longitudinal passages vextending through the refractory ining of the retort and opening at the ends thereof' through registering apertures in the Specification of Letters Patent. application filed October'lS,

ROTARY ELECTRIC FURNACE.

Patented July 3, 1906. 190a Serial No. 176.85%. I

end plates. In operation said passages are filled with powdered coke or graphite or with a divided carbonaceous mixture which will offer, sufficient resistance to the current to develop the desired temperature. When the furnace is mounted in an inclined position,

the lower ends of said passages are closed by closely-fitting blocks or plugs '10, preferably of graphite, to which electrical connection is -made in any approved-nianner. A similar closure and contact may be applied to the upper endiof the furnace.

one means for making electrical con- 12 are applied. In thiscase said blocks 10 may'be insulated from the end plates of the furnace I do not, however, limit myself to any particular form of contact device, but may, if desired, use the end plates of the furnace for making contact with the several blocks 10, applying the brush to an axial projection from said plates. One of said projections may, if desired, be tubular and serve as the eduction-pipe for the volatile reaction products. I k

I have illustrated the passages 8 as rectangular in section, substantially uniform in cross-sectional area, and as lying parallel to the inner wallof the furnace. understood, however, that in one or all of these respects I may introduce such modifications as will serve to secure a proper distribution of heat within the furnace-cham ber. For instance, it is often desirable to produce a graduated temperature within the muflie, the temperature being highest near the lower or discharge end and decreasing It will be toward the eduction-pipe for the metallic which it is desired to develop the highest temperature.

Thus a graduated tempera- 'ture development may be secured fromend to-end of the furnace by a gradedadmiXture of non-conductive material with the divided conductor.

- The retort is provided with asuitable eduction-pipe 13 for the metallic vapors, said pipe communicating with suitable condensers and with an exhaust or pressure pump in case it be desired to work under diminished or increased pressure'. The retort is mounted upon suitable roller-bearings 14 15, one or both sets of which may be coned, as-indicated at 15, or otherwise formed to prevent longitudinal displacement of the furnace; Any suitable means for imparting a rotary move ment may be provided. As one such means I l ave indicated the use of a rack 16 and pinion 17.

.I clain1 1. A rotatable electric furnace comprising a chamber composed of separable sections provided with refractory linings, a resistanceconductor for heating said chamber, and means for rotating said furnace substantially as described.

2. A rotatable electric furnace comprising a chamber composed of separable sections provided with refractory linings, insulating.

material between said sections, a resistanceconductor for heating said chamber, and means for rotating said furnace substantially as described.

3. A rotatable electric furnace comprising a chamber composed of separable sections provided with refractory linings, resistanceconductors within said linings, and means for rotating said furnace substantially as described.

4. A rotatable electric furnace comprising a chamber composed of separable sections provided with refractory linings, a resistancebody of divided conductive material within said linings, and means for rotating said furnace substantially as described.

In testimony whereof I affix my signature in presence of two witnesses. WOOLSEY McA. JOHNSON. Witnesses:

CHARLES M. STARKWEATHER, JOHN FELT Momns. 

